1. Field of the Invention
The invention is directed to a suspended ceiling grid construction and, more particularly, to the end detail structure of a cross tee and its cooperating structure on the main runner of a suspended ceiling system.
2. Description of the Prior Art
For many years, suspended ceiling systems were put together with a grid structure that had the main runner elements and cross tee elements permanently affixed together. In recent years, there have been many developments towards the use of ceiling systems with grid members which can be readily snapped together and then disassembled in toto, if desired, at a later date. Finally, a ceiling system was developed wherein one could remove any cross tee without damage at any point within the ceiling and subsequently replace the same cross tee.
U.S. Pat. No. 3,169,614 is typical of the current commercial suspended ceiling grid structures as last above described. The cross tee 13 is provided with a tongue 24 which engages two tabs 31. A locking dimple 34 is used to position the tongue in position relative the holding tabs 31. The problem encountered with this system is that the locking dimple 34 does not provide for a positive alignment of the cross tees relative each other. If an installer is not careful, the tongue will not be correctly engaged on the locking dimple 34 and the tees will show a wavey line structure when a number of them are viewed across a ceiling system.
U.S. Pat. No. 2,990,921 is directed to a connecting joint for a cross tee and main runner wherein alignment may be secured between a plurality of cross tees. Tongues 10 on the cross tee engage ears 4 on a main runner structure. The attaching structure is made as an element separate from the main body of the cross runner structure.
U.S. Pat. No. 2,896,752 is directed to a structure similar to that of the aforementioned patent except that a single tab is utilized to engage a single ear 10 on the main runner structure so as to lock the cross tee in position relative the main runner structure.
The invention herein is designed to provide the simplicity of structure such as that found in U.S. Pat. No. 3,169,614, while at the same time providing the positive alignment between a number of cross tees such as one would find in the above-mentioned other two U.S. patents.